Growing Up - My Bark

Notice how the American chestnut tree's bark is rough with deep furrows.
As we trees age, we shed our protective outer bark. Since our bark is no longer alive, it cannot grow. Usually it peels or cracks; it then expands as we grow fatter.

TRIVIA: Suppose you carve your initials in the bark of a tree 4 feet above the ground. One or two decades later, you return to the same tree. How much higher up the tree will your initials be?